Sts. & Hy. Code, § 19180

On or before the first day of September of each year, the governing body shall make an estimate of the cost, not otherwise offset by other available revenue, of conducting and maintaining the district for the ensuing fiscal year, and shall include therein the cost of installing and maintaining such additional lights as may have been petitioned for by the residents of the district as well as the cost of any other things which may be necessary or proper for carrying out the purposes of this part, including a levy of tax or assessment not to exceed 10 percent of the total levy for other purposes for the purpose of accumulating reserve for installation of additional lights which, in the opinion of the governing board, may be petitioned for before the proceeds of another tax or assessment levy will be available for use for such purposes.